Enterococcus faecium as a Surrogate of Salmonella: It Works for Almonds, But Does It Work for My Products?

Validation of food processing equipment often requires the in-facility use of a nonpathogenic surrogate organism. The organism should have similar or more robust survival capabilities under the conditions being studied and, ideally, have been characterized with respect to pathogenicity or lack thereof. Historically, Enterococcus faecium NRRL B-2354 has been used as a surrogate for foodborne pathogens in thermal processes used for dairy products, juice, and meat. Under a wide range of laboratory and pilot-scale conditions, the thermal tolerance of this organism on almonds has been shown to be similar to that of Salmonella. As a result E. faecium NRRL B-2354 is recommended and widely used as a surrogate for Salmonella in the validation of commercial thermal processes that are used for almonds. The organism has also been adopted as a surrogate for Salmonella and other enteric pathogens in a wide range of low-moisture foods and a wide range of thermal and non-thermal processes. The assumptions supporting this adoption and the data needs will be discussed.